import { saveAs } from 'file-saver';
import * as XLSX from 'xlsx';
import * as XLSX_STYLE from 'xlsx-style-vite';

function datenum(v, date1904) {
  if (date1904) v += 1462;
  var epoch = Date.parse(v);
  return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000);
}

function sheet_from_array_of_arrays(data) {
  var ws = {};
  var range = {
    s: {
      c: 10000000,
      r: 10000000,
    },
    e: {
      c: 0,
      r: 0,
    },
  };
  for (var R = 0; R != data.length; ++R) {
    for (var C = 0; C != data[R].length; ++C) {
      if (range.s.r > R) range.s.r = R;
      if (range.s.c > C) range.s.c = C;
      if (range.e.r < R) range.e.r = R;
      if (range.e.c < C) range.e.c = C;
      var cell = {
        v: data[R][C],
      };
      if (cell.v == null) continue;
      var cell_ref = XLSX.utils.encode_cell({
        c: C,
        r: R,
      });

      if (typeof cell.v === 'number') cell.t = 'n';
      else if (typeof cell.v === 'boolean') cell.t = 'b';
      else if (cell.v instanceof Date) {
        cell.t = 'n';
        cell.z = XLSX.SSF._table[14];
        cell.v = datenum(cell.v);
      } else cell.t = 's';
      ws[cell_ref] = cell;
    }
  }
  if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range);
  return ws;
}

function Workbook() {
  if (!(this instanceof Workbook)) return new Workbook();
  this.SheetNames = [];
  this.Sheets = {};
}

function s2ab(s) {
  var buf = new ArrayBuffer(s.length);
  var view = new Uint8Array(buf);
  for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xff;
  return buf;
}

export function export_json_to_excel({
  multiHeader = [],
  header,
  data,
  sheetname,
  filename,
  merges = [],
  autoWidth = true,
  bookType = 'xlsx',
} = {}) {
  filename = filename || 'excel-list';
  data = [...data];

  for (var i = 0; i < header.length; i++) {
    data[i].unshift(header[i]);
  }

  for (var i = 0; i < data.length; i++) {
    data[i].unshift(multiHeader);
  }
  var ws_name = sheetname;
  var wb = new Workbook(),
    ws = [];
  for (var j = 0; j < header.length; j++) {
    ws.push(sheet_from_array_of_arrays(data[j]));
  }
  ws.forEach(item => {
    for (let key in item) {
      if (key == '!ref' || key == '!merges' || key == '!cols' || key == '!rows') {
        return;
      } else if (key == 'A1') {
        item[key].s = {
          alignment: {
            horizontal: 'left',
            vertical: 'center',
            wrapText: false,
            indent: 0,
          },
          fill: {
            fgColor: { rgb: 'ffffff' },
          },
        };
      } else if (key.match(/\d+/g).join('') == '2') {
        item[key].s = {
          border: {
            top: {
              style: 'thin',
            },
            bottom: {
              style: 'thin',
            },
            left: {
              style: 'thin',
            },
            right: {
              style: 'thin',
            },
          },
          fill: {
            fgColor: { rgb: 'dddddd' },
          },
          alignment: {
            horizontal: 'center',
            vertical: 'center',
            wrapText: false,
            indent: 0,
          },
        };
      } else {
        item[key].s = {
          border: {
            top: {
              style: 'thin',
            },
            bottom: {
              style: 'thin',
            },
            left: {
              style: 'thin',
            },
            right: {
              style: 'thin',
            },
          },
          fill: {
            fgColor: { rgb: 'ffffff' },
          },
          alignment: {
            horizontal: 'center',
            vertical: 'center',
            wrapText: false,
            indent: 0,
          },
        };
      }
    }
  });

  let mergesArr = [];
  const cellArr = [
    'A',
    'B',
    'C',
    'D',
    'E',
    'F',
    'G',
    'H',
    'I',
    'J',
    'K',
    'L',
    'M',
    'N',
    'O',
    'P',
    'Q',
    'R',
    'S',
    'T',
    'U',
    'V',
    'W',
    'X',
    'Y',
    'Z',
    'AA',
    'AB',
    'AC',
    'AD',
    'AE',
    'AF',
    'AG',
    'AH',
    'AI',
    'AJ',
    'AK',
    'AL',
    'AM',
    'AN',
    'AO',
    'AP',
    'AQ',
    'AR',
    'AS',
    'AT',
    'AU',
    'AV',
    'AW',
    'AX',
    'AY',
    'AZ',
  ];
  data.forEach(item => {
    const cell = 'A1:' + cellArr[item[1].length - 1] + '1';
    mergesArr.push(cell);
  });
  if (ws.length > 0) {
    ws.forEach((wsItem, wsIndex) => {
      if (!wsItem['!merges']) wsItem['!merges'] = [];
      wsItem['!merges'].push(XLSX.utils.decode_range(mergesArr[wsIndex]));
      if (!wsItem['!rows']) wsItem['!rows'] = [];
      wsItem['!rows'] = [
        { hpt: 150, hpx: 150 },
        { hpt: 30, hpx: 30 },
      ];
    });
  } else {
    if (!ws['!merges']) ws['!merges'] = [];
    merges.forEach(item => {
      ws['!merges'].push(XLSX.utils.decode_range(item));
    });
  }

  if (autoWidth) {
    var colWidth = [];
    for (var k = 0; k < header.length; k++) {
      colWidth.push(
        data[k].map(row =>
          row.map(val => {
            if (val == null) {
              return {
                wch: 10,
              };
            } else if (val.toString().charCodeAt(0) > 255) {
              return {
                wch: val.toString().length * 3,
              };
            } else {
              return {
                wch: val.toString().length + 15,
              };
            }
          })
        )
      );
    }

    let result = [];
    for (var k = 0; k < colWidth.length; k++) {
      result[k] = colWidth[k][1];
      for (let i = 1; i < colWidth[k].length; i++) {
        for (let j = 0; j < colWidth[k][i].length; j++) {
          if (result[k][j]['wch'] < colWidth[k][i][j]['wch']) {
            result[k][j]['wch'] = colWidth[k][i][j]['wch'];
          }
        }
      }
    }

    for (var l = 0; l < result.length; l++) {
      ws[l]['!cols'] = result[l];
    }
  }

  for (var k = 0; k < header.length; k++) {
    wb.SheetNames.push(ws_name[k]);
    wb.Sheets[ws_name[k]] = ws[k];
  }

  var wbout = XLSX_STYLE.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: 'binary',
  });

  saveAs(
    new Blob([s2ab(wbout)], {
      type: 'application/octet-stream',
    }),
    `${filename}.${bookType}`
  );
}
